Hong Kong (CNN) -- A construction worker found what appears to be a World War II-era bomb Thursday afternoon at a work site on Hong Kong Island, prompting evacuations in the area, police told CNN.

The suspected bomb was found upright in the ground as workers dug at a construction site for a hotel, the police told CNN. Initial police analysis suggested it was American ordnance, designated US Navy ANM 66.

People within 500 meters of the site were told to leave by 8 p.m. (7 a.m. ET), the Chinese news agency Xinhua reported, citing police. The evacuation area included the neighboring Cosmopolitan Hotel.

Map: Hong Kong Island

Police didn't immediately know how many people would be evacuated, police spokesperson Florence Ma told CNN.

A team of at least six bomb disposal officers in protective clothing was seen at the site. A police spokesperson said that they would not attempt a controlled detonation on site.

Neither the condition of the casing nor the integrity of the device could not immediately be confirmed.

The scene was calm Thursday night. Firetrucks, ambulances and roughly two dozen police officers were there, but traffic was flowing on the nearby main road, and there appeared to be no onlookers, save for a small group of reporters.

Traffic was stopped on roads leading to the site, resulting in a line of several waiting buses. Police gave passengers the option to alight but most waited for the cordon to be lifted.

Such a discovery isn't unheard of, and unexploded bombs from World War II raids have been found in Hong Kong hillsides and construction sites, the police spokesman said.

Bombs from that era also have been found in Europe. Last month, a bulldozer struck what authorities believed was a World War II-era bomb in the western German town of Euskirchen, causing a blast that killed the bulldozer driver, injured a number of other people and damaged homes, police said.